Prosthetic devices

ABSTRACT

A prosthetic device made of a first specific type of polyarylene, taken alone or in combination with a second specific type of polyarylene, featuring some unexpected advantages such as a very high strength and stiffness, good elongation properties, high chemical resistance, good biocompatibility as well as an outstanding impact resistance.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/676,989, filed Apr. 21, 2010, now U.S. Pat. No. 8,592,531; which is aU.S. national stage application under 35 U.S.C. §371 of InternationalApplication No. PCT/EP2008/061948 filed Sep. 9, 2008, which claimspriority to and benefit under 35 U.S.C. §119(e) to U.S. provisionalapplication No. 60/971,314 filed Sep. 11, 2007 and to U.S. provisionalapplication No. 60/971,934 filed Sep. 13, 2007, the whole content ofthese applications being incorporated herein by reference for allpurposes.

This application claims priority to and benefit under 35 U.S.C. §119(e)to U.S. provisional application No. 60/971,314 filed Sep. 11, 2007 andto U.S. provisional application No. 60/971,934 filed Sep. 13, 2007, thewhole content of these applications being incorporated herein byreference for all purposes.

FIELD OF THE INVENTION

The present invention is related to a prosthetic device made of a firstspecific type of polyarylene, taken alone or in combination with asecond specific type of polyarylene. Such prosthetic device featuressome unexpected advantages.

BACKGROUND OF THE INVENTION

Due both to demographic change and to developments in medical science,the number of surgical procedures involving prosthesis implantation isrising rapidly. The more obvious examples of prosthetic devices are hipor knee replacements and false teeth. Other less well-known examples arestents, heart valves, bone screws and plates and spinal fixators.

Prosthesis must be tolerated by the patient and not altered in time.Materials that may be suitable for each type of prosthesis are subjectedto precise specifications. Indeed, if the prosthesis is a dental implantor a hip replacement the specifications will be very different. The mostimportant requirements are mechanical properties similar to those ofbone to allow the transfer constraints between bone and prosthesis,chemical resistance to corrosion, chemical inertia in relation to theenvironment and biocompatibility. These properties must be controlled tomaintain the integrity of used materials. The human body is anaggressive and corrosive environment mainly because of concentrations ofchloride ions (113 mEq/l in blood plasma and 117 mEq/l in theinterstitial fluid, which is sufficient to corrode metallic materials)and dissolved oxygen. For dental implants, conditions are even toughersince the saliva contains more sulfur products that make it still morecorrosive. The term “biocompatibility” is defined by the Dorland'sMedical Dictionnary as the quality of not having toxic or injuriouseffects on biological systems. This encompasses both the material andhost responses to an implant. The host response to an implant can behighly complex and is often linked to the material response. It is alsodependent on the anatomical position of the implant. For a material tobe biocompatible, it should not elicit any adverse host reactions to itspresence. Inflammation and encapsulation phenomena may occur when theprosthesis suffer from low biocompatibility.

Typically, prosthetic devices are made of inorganic (metal, alloys,ceramic and glass) and/or polymeric materials.

It is a fact that most pure metals and alloys are chemically unstable inmany everyday environments due to their tendency to corrode. In thecomplex environment of the human body, metals and alloys are subject toelectrochemical corrosion mechanisms, with bodily fluids acting as anelectrolyte. While alloys such as stainless steel may appear to behighly stable and are widely used for kitchenware, eating utensils andjewelry, there are many situations that can cause severe corrosion ofthis material, and it is not the best choice for use in prostheticdevices.

Compared to inorganic materials, polymeric materials have certainadvantages: they are lightweight, corrosion resistant, they can bedirectly shaped by molding and offer design freedoms. Over the past 4years, the price of steel and non-ferrous metals grew faster thanpolymers and they require also less energy to be implemented. Amongvarious existing polymers, only some of them have been used in theprosthesis industry so far, mainly because of their biocompatibility.Examples of such polymers are polymethyl methacrylate, polystyrene,poly(ether ether ketone) . . . .

Polyarylenes exhibit some outstanding performance properties, includingexceptionally high strength, stiffness, hardness, scratch resistance,dimensional stability, great friction and wear properties, high solventresistance and exceptional low temperature performance. These propertiesmake them excellent candidates for end-use applications such as:mechanical components, aircraft interiors, coatings . . . .

In general, the so far known polyarylenes, while offering anexceptionally high level of strength and stiffness (which often evenexceeds the needs of the applications wherein they are used) sufferirremediably from limitations in toughness-related properties:

-   -   they have limited elongability;    -   they have limited impact resistance (as typically characterized        by standard notched and unnotched Izod tests).

They also have also limitations in melt processability due to their highviscosities, and tend to be anisotropic when melt fabricated under highshear such as during injection molding. Also, they have some limitationsin chemical resistance.

All materials used in the prior art prosthetic devices and known to theApplicant still suffer from a limited impact resistance, which is a keyproperty for such application where such materials are submitted tovarious and harsh conditions.

There remains thus a strong need for a prosthetic device presenting asuperior balance of properties, including part or preferably all of thefollowing ones:

-   -   very high strength;    -   very high stiffness;    -   good elongation properties;    -   good melt processability (in particular, good injection        moldability);    -   high chemical resistance;    -   good biocompatibility;    -   outstanding impact resistance, as possibly characterized by a        standard no-notch IZOD test (ASTM D-4810).

In fact, there is a specific need to improve the mechanical propertiesof the existing prosthetic devices and in particular their impactresistance while at least maintaining their biocompatibility.

The Applicant has found that a first specific type of polyarylene, takenalone or in combination with a second specific type of polyarylene offersurprisingly and in particular a good biocompatibility and impactresistance. This outstanding property may be useful in certain demandingapplications, such as articles used as prosthetic devices.

It has been surprisingly found that the materials comprising:

-   (i) at least one polyarylene (P2) of another specific type,    characterized by a “high” amount of kink-forming arylene units (up    to 100%) such as Primospire® PR-250 polyphenylene, and optionally;-   (ii) at least one polyarylene (P1) of a first specific type,    characterized by a “low” amount (down to 0%) of kink-forming arylene    units such as

Primospire® PR-120 polyphenylene (formerly Parmax® 1200); arecharacterized by very good impact resistance properties. The intendedmeaning of the terms “low” and “high” will become clear in the light ofwhat follows.

These outstanding properties have already been described inEP2007/052095, the content of which is incorporated by reference, whichillustrates some of the surprising behaviors related to these specificmaterials.

The present invention is thus related to a prosthetic device comprisingat least one part consisting of a material comprising at least onepolyarylene (P2), of which the efficient arylene recurring units (R2)are a mix (M2) consisting of:

-   -   less than 70 mole %, down to 0 mole %, based on the total number        of moles of efficient arylene recurring units (R2), of rigid        rod-forming arylene units (Ra), said rigid rod-forming arylene        units (Ra) being optionally substituted by at least one        monovalent substituting group        with    -   more than 30 mole %, up to 100 mole %, based on the total number        of moles of efficient arylene recurring units (R2), of        kink-forming arylene units (Rb), said kink-forming arylene units        being optionally substituted by at least one monovalent        substituting group.

The present invention is also related to a prosthetic device comprisingat least one part consisting of a material comprising: at least onepolyarylene (P2), of which the efficient arylene recurring units (R2)are a mix (M2) consisting of:

-   -   less than 70 mole %, down to 0 mole %, based on the total number        of moles of efficient arylene recurring units (R2), of rigid        rod-forming arylene units (Ra), said rigid rod-forming arylene        units (Ra) being optionally substituted by at least one        monovalent substituting group        with    -   more than 30 mole %, up to 100 mole %, based on the total number        of moles of efficient arylene recurring units (R2), of        kink-forming arylene units (Rb), said kink-forming arylene units        being optionally substituted by at least one monovalent        substituting group.        and        at least one polyarylene (P1), of which the efficient arylene        recurring        units (R1) are a mix (M1) consisting of:    -   from 70 mole % to 100 mole %, based on the total number of moles        of efficient arylene recurring units (R1), of rigid rod-forming        arylene units (Ra), said rigid rod-forming arylene units (Ra)        being optionally substituted by at least one monovalent        substituting group        with    -   from 0 to 30 mole %, based on the total number of moles of        efficient arylene recurring units (R1), of kink-forming arylene        units (Rb), said kink-forming arylene units being optionally        substituted by at least one monovalent substituting group.

The prosthetic devices of the present invention feature some unexpectedadvantages because of the materials of which they are made.

BRIEF DESCRIPTION OF THE FIGURES

Illustrated in sectional view in the drawings are, in FIG. 1, a cranialplate 1 in situ within an aperture cut into the skull 2; in FIG. 2 aninsert 3 in a long bone 4 from which part of the bone had been removed;and in FIG. 3 a femur head replacement 5 in situ within a femur 6. Thislast device comprises a core component 7 of a cement composition asdescribed in European Patent Specification No. 21682 and comprising asurface coating of polyarylene (P2) and polyarylene (P1) 8, a bearingsurface 9 of titanium and a fibrous surface layer 10.

A bone plate shown in perspective in FIG. 4 is shown also in enlargedsection in FIG. 5, to illustrate the use of a polyarylene (P2) andpolyarylene (P1) outer coating 11 upon a core region comprising apolyarylene (P2) and polyarylene (P1)-carbon fibre composite 12. FIG. 6shows the presence of polyarylene (P2) and polyarylene (P1) 13 alsoafter refilling of the screw holes and redrilling.

DETAILED DESCRIPTION OF THE INVENTION The Prosthetic Device

To the purposes of the invention, the term “prosthetic device” isintended to denote an artificial device which is made to replace and actas a missing biological structure. Prosthetic devices may havestructural features which make them suitable to act as reinforcement orreplacement of a missing or defective animal or human body part, e.g. abone implant. Prosthetic devices of many shapes, configurations andproperties are commonly employed within the living body. They can beused to replace parts lost by injury (traumatic or chirurgical) ormissing from birth (congenital) or to supplement defective body parts.

For the sake of clarity, the term “part of a prosthetic device” isintended to denote a piece or portion which is combined with others tomake up the whole prosthetic device. The external coating of aprosthetic device falls thus within this scope.

The prosthetic device of the present invention may comprise additionalparts. Additional parts are intended to denote parts of the prostheticdevices which do not aim to replace a part of the body as such, butperform a supplementary function. For instance, it may comprise metalinserts, structural reinforcements, radio-opaque inserts, movingmotor-driven assemblies, electronic devices, controlling units and thelike.

The prosthetic device according to the present invention may be anorthopaedic prosthesis for building and/or repairing and/or improvingsurface properties of skeletal bones and joints such as, but not limitedto ligaments, tendons, cartilage, bones, hip joints, knee prosthesis,spinal disc orthoprosthesis.

Orthopaedic prostheses comprise manufactured replacements for the endsand articulating surfaces of the bones of the skeleton. Such prosthesesare generally implanted to repair or reconstruct all or part of anarticulating skeletal joint that is functioning abnormally due todisease, trauma or congenital defect. Other forms of implantableorthopaedic prostheses, beyond providing manufactured replacements forthe ends and articulating surfaces of the bones of the skeletal joints,also provide manufactured replacements for portions of the bones distantfrom the articulating surface. These other forms may be used in cases ofabnormally extensive atrophy or resorption of bone in the vicinity ofthe articulating surface or prior implant, or in cases where anextensive amount of bone is to be intentionally resected to treatoncological or other diseases of the bone. Because the natural bonyareas to which ligaments, tendons and other soft tissues attach areoften lost to such extensive resections of the bone, implantableorthopaedic implants designed for such cases often include means forattaching bone and/or soft tissue directly to the implant. Generallysuch means also provide an initial mechanical attachment, supplementedby later ingrowth and ongrowth of the bone and soft tissue to theprosthesis.

Example of such prosthetic devices are described in many patentreferences, such as in U.S. Pat. No. 4,164,794A, U.S. Pat. No.4,351,069A, U.S. Pat. No. 4,662,887A, U.S. Pat. No. 5,064,439A, U.S.Pat. No. 5,219,363A, U.S. Pat. No. 5,397,365A, U.S. Pat. No. 5,443,512A,U.S. Pat. No. 5,176,710A, U.S. Pat. No. 5,181,930A, GB 2,259,253A1, U.S.Pat. No. 5,370,696A, U.S. Pat. No. 5,236,457A, EP 0598450A1, U.S. Pat.No. 5,872,159A, EP 0761242A1, U.S. Pat. No. 5,782,930A, U.S. Pat. No.6,602,293B, GB 2,319,962A1, DE 19728131A1, DE 19823737A1, US2002107577A, US 2002111691A, WO 02070031A1, US 2002099449A, US2002115742A, US 2002120336A, US2004158324A, WO 02071959A1, US2002173850A, US 2003004563A, US 2003135275A, US 2003195327A, US2004059356A, DE 10256345C1, BE 1015402AG, US 2004249471A, CN 1582860A,US 2005228498A, US 2005136764A, WO 05096759A2, CN 1593356A, WO06039636A2, US 2006116774A, US 2006200245A, US 2006241759A, US2006247638A, WO 07051307A2 and EP 1813292A, the whole content of all ofthem being herein incorporated by reference.

For example, the prosthetic device of the present invention may beselected from the group consisting of:

-   -   orthopaedic prosthesis such as ligaments, tendons, cartilage,        bones, hip joints, knee prosthesis, spinal disc orthoprosthesis;    -   dental structures such as dentures, partial dentures;    -   prosthetic structures for other body parts, such as prosthetic        devices that serve as artificial body parts including limbs,        eyes, implants, included cosmetic implants, hearing aids, and        the like, such as spectacle frames;    -   fixed prosthetic anatomical devices such as caps, crowns and        other non-dental anatomical replacement structures.        The Polyarylenes (P1) and (P2)        Features Common to Polyarylenes (P1) and (P2)

For the sake of clarity, all the definitions and preferences expressedin the present chapter “Features common to polyarylenes (P1) and (P2)”,whatever their concern and whatever the level of preference expressed,can be applied independently from each other to polyarylene (P1) and topolyarylene (P2).

For the purpose of the present invention, an arylene group is ahydrocarbon divalent group consisting of one core composed of onebenzenic ring or of a plurality of benzenic rings fused together bysharing two or more neighboring ring carbon atoms, and of two ends.

Non limitative examples of arylene groups are phenylenes, naphthylenes,anthrylenes, phenanthrylenes, tetracenylenes, triphenylylenes,pyrenylenes, and perylenylenes. The arylene groups (especially thenumbering of the ring carbon atoms) were named in accordance with therecommendations of the CRC Handbook of Chemistry and Physics, 64^(th)edition, pages C1-C44, especially p. C11-C12.

Arylene groups present usually a certain level of aromaticity; for thisreason, they are often reported as “aromatic” groups. The level ofaromaticity of the arylene groups depends on the nature of the arylenegroup; as thoroughly explained in Chem. Rev. 2003, 103, 3449-3605,“Aromaticity of Polycyclic Conjugated Hydrocarbons”, the level ofaromaticity of a polycyclic aromatic hydrocarbon can be notablyquantified by the “index of benzene character” B, as defined on p. 3531of the same paper; values of B for a large set of polycyclic aromatichydrocarbon are reported on table 40, same page.

An end of an arylene group is a free electron of a carbon atom containedin a (or the) benzenic ring of the arylene group, wherein an hydrogenatom linked to said carbon atom has been removed. Each end of an arylenegroup is capable of forming a linkage with another chemical group. Anend of an arylene group, or more precisely the linkage capable of beingformed by said end, can be characterized by a direction and by a sense;to the purpose of the present invention, the sense of the end of anarylene group is defined as going from the inside of the core of thearylene group to the outside of said core. As concerns more preciselyarylene groups the ends of which have the same direction, such ends canbe either of the same or opposite sense; also, their ends can be in thestraight foregoing of each other, or not (otherwise said, they can bedisjoint).

The polyarylenes (P1) and (P2) are polyarylenes, in that they arepolymers of which more than 50 wt. % of the recurring units areefficient arylene recurring units, respectively named recurring (R1)[for the polyarylene (P1)] and (R2) [for the polyarylene (P2)].

Hereinafter, recurring units (R) denote indifferently recurring units(R1) or recurring units (R2). As already above stated, all thedefinitions and preferences expressed in the present chapter, whatevertheir concern and whatever the level of preference expressed, can beapplied independently from each other to polyarylene (P1) and topolyarylene (P2); thus, in particular, all the definitions andpreferences expressed in the present chapter regarding recurring units(R) can be applied independently from each other to recurring units (R1)and recurring units (R2).

Efficient arylene recurring units (R) are:

-   -   arylene units, in that they are of one or more formulae        consisting of an optionally substituted arylene group;    -   efficient, in that said optionally substituted arylene group is        linked by each of its two ends to two other optionally        substituted arylene groups via a direct C—C linkage.

That the optionally substituted arylene group is linked by each of itstwo ends to two other optionally substituted arylene groups via a directC—C linkage, is an essential feature of the efficient arylene recurringunits (R). Thus, an arylene recurring unit which is linked by at leastone of its two ends to a group other than an arylene group such asphenylene recurring units φ₁, φ₂ and φ_(2′) below:

-   O-φ₁-S(═O)₂—,-   O-φ₂-φ_(2′)-O—    are not efficient arylene recurring units (R) in the sense of the    present invention.

The arylene groups of which the efficient arylene recurring units (R)consist can be unsubstituted. Alternatively, they can be substituted byat least one monovalent substituting group.

The monovalent substituting group is usually not polymeric in nature;its molecular weight is preferably below 500, more preferably below 300,still more preferably below 200 and most preferably below 150.

Should the optionally substituted group be effectively substituted by atleast one monovalent substituting group, said monovalent substitutinggroup is advantageously a solubilizing group. A solubilizing group isone increasing the solubility of the polyarylene of concern in at leastone organic solvent, in particular in at least one of dimethylformamide,N-methylpyrrolidinone, hexamethylphosphoric triamide, benzene,tetrahydrofuran and dimethoxyethane, which can be used as solventsduring the synthesis of the polyarylene by a solution polymerizationprocess.

The monovalent substituting group is also advantageously a group whichincreases the fusibility of the polyarylene, i.e. it lowers its glasstransition temperature and its melt viscosity, so as to desirably makethe polyarylene suitable for thermoprocessing.

Preferably, the monovalent substituting group is chosen from:

-   -   hydrocarbyls such as alkyls, aryls, alkylaryls and aralkyls;    -   halogens such as —Cl, —Br, —F and —I;    -   hydrocarbyl groups partially or completely substituted by at        least one halogen atom such as halogenoalkyls, halogenoaryls,        halogenoalkylaryls and halogenoaralkyls;    -   hydroxyl;    -   hydrocarbyl groups substituted by at least one hydroxyl group,        such as hydroxyalkyls, hydroxyaryls, hydroxyalkylaryls and        hydroxyaralkyls;    -   hydrocarbyloxys [—O—R, where R is a hydrocarbyl group], such as        alkoxys, aryloxys, alkylaryloxys and aralkyloxys;    -   amino (—NH₂);    -   hydrocarbyl groups substituted by at least one amino group, such        as aminoalkyls and aminoaryls;    -   hydrocarbylamines [—NHR or —NR₂, where R is a hydrocarbyl group]        such as alkylamines and arylamines;    -   carboxylic acids and their metal or ammonium salts, carboxylic        acid halides, carboxylic anhydrides;    -   hydrocarbyl groups substituted by at least one of carboxylic        acids, metals or ammonium salts thereof, carboxylic acid halides        and carboxylic anhydrides, such as —R—C(═O)OH where R is an        alkyl or an aryl group;    -   hydrocarbylesters [—C(═O)OR or —O—C(═O)R, where R is a        hydrocarbyl group] such as alkylesters, arylesters,        alkylarylesters and aralkylesters;    -   amido [—C(═O)NH₂];    -   hydrocarbyl groups substituted by at least one amido group;    -   hydrocarbylamide monoesters [—C(═O)NHR or —NH—C(═O)—R, where R        is a hydrocarbyl group], such as alkylamides, arylamides,        alkylarylamides and aralkylamides, and hydrocarbylamide diesters        [—C(═O)NR₂ or —N—C(═O)R₂, where R are a hydrocarbyl groups],        such as dialkylamides and diarylamides;    -   sulfinic acid (—SO₂H), sulfonic acid (—SO₃H), their metal or        ammonium salts;    -   hydrocarbylsulfones [—S(═O)₂—R, where R is the hydrocarbyl        group], such as alkylsulfones, arylsulfones, alkylarylsulfones,        aralkylsulfones;    -   aldehyde [—C(═O)H] and haloformyls [—C(═O)X, wherein X is a        halogen atom];    -   hydrocarbylketones [—C(═O)—R, where R is a hydrocarbyl group],        such as alkylketones, arylketones, alkylarylketones and        aralkylketones;    -   hydrocarbyloxyhydrocarbylketones [—C(═O)—R¹—O—R², where R¹ is a        divalent hydrocarbon group such as an alkylene, an arylene, an        alkylarylene or an aralkylene, preferably a C₁-C₁₈ alkylene, a        phenylene, a phenylene group substituted by at least one alkyl        group, or an alkylene group substituted by at least one phenyl        group; and R² is a hydrocarbyl group, such as an alkyl, aryl,        alkylaryl or aralkyl group], such as alkyloxyalkylketones,        alkyloxyarylketones, alkyloxyalkylarylketones,        alkyloxyaralkylketones, aryloxyalkylketones, aryloxyarylketones,        aryloxyalkylarylketones and aryloxyaralkylketones;    -   any of the above groups comprising at least one hydrocarbyl        group or a divalent hydrocarbon group R¹, wherein said        hydrocarbyl group or said R¹ is itself substituted by at least        one of the above listed monovalent substituting groups, e.g. an        arylketone —C(═O)—R, where R is an aryl group substituted by one        hydroxyl group;        where:    -   the hydrocarbyl groups contain preferably from 1 and 30 carbon        atoms, more preferably from 1 to 12 carbon atoms and still more        preferably from 1 to 6 carbon atoms;    -   the alkyl groups contain preferably from 1 to 18 carbon atoms,        and more preferably from 1 to 6 carbon atoms; very preferably,        they are chosen from methyl, ethyl, n-propyl, isopropyl,        n-butyl, isobutyl and tert-butyl;    -   the aryl groups are defined as monovalent groups consisting of        one end and one core composed of one benzenic ring (such the        phenyl group) or of a plurality of benzenic rings directly        linked to each other via a carbon-carbon linkage (such as the        biphenyl group) or fused together by sharing two or more        neighboring ring carbon atoms (such as the naphthyl groups), and        wherein the ring carbon atoms are possibly substituted by at        least one nitrogen, oxygen or sulfur atom; preferably, in the        aryl groups, no ring carbon atom is substituted;    -   the aryl groups contain preferably from 6 to 30 carbon atoms;        more preferably, they are phenyl groups;    -   the alkyl group which is contained in the alkylaryl groups meets        the preferences of the alkyl groups as above expressed;    -   the aryl group which is contained in the aralkyl groups meets        the preferences of the aryl groups as above expressed.

More preferably, the monovalent substituting group is chosen fromhydrocarbylketones [—C(═O)—R, where R is a hydrocarbyl group] andhydrocarbyloxyhydrocarbylketones [—C(═O)—R¹—O—R², where R¹ is a divalenthydrocarbon group and R² is a hydrocarbyl group], saidhydrocarbylketones and hydrocarbyloxyhydrocarbylketones beingunsubstituted or substituted by at least one of the above listedmonovalent substituting groups.

Still more preferably, the monovalent substituting group is chosen fromarylketones and aryloxyarylketones, said arylketones andaryloxyarylketones being unsubstituted or substituted by at least one ofthe above listed monovalent substituting groups.

Most preferably, the monovalent substituting group is an (unsubstituted)arylketone, in particular it is phenylketone [—C(═O)-phenyl].

The core of the optionally substituted arylene group of the efficientarylene recurring units (R), is composed of preferably at most 3, morepreferably at most 2, and still more preferably at most one benzenicring. Then, when the core of the optionally substituted arylene group ofthe efficient arylene recurring units (R) is composed of one benzenicring, the efficient arylene recurring units (R) are of one or moreformulae consisting of an optionally substituted phenylene group,provided said optionally substituted phenylene group is linked by eachof its two ends to two other optionally substituted arylene groups via adirect C—C linkage.

As above explained, the optionally substituted arylene group of theefficient arylene recurring units (R) is linked by each of its two endsto two other optionally substituted arylene groups via a direct C—Clinkage. Preferably, it is linked by each of its two ends to two otheroptionally substituted phenylene groups via a direct C—C linkage.

As also above explained, both ends of the optionally substituted arylenegroup of the efficient arylene recurring units (R) can be characterizednotably by a direction and by a sense.

A first set of possible efficient arylene recurring units (R) iscomposed of optionally substituted arylene groups, the ends of which

-   -   have the same direction,    -   are of opposite sense, and    -   are in the straight foregoing of each other        [hereafter, rigid rod-forming arylene units (Ra)].

As already explained for recurring units (R) in general, rigidrod-forming arylene units (Ra) are efficient, in that they are linked byeach of their two ends to two other optionally substituted arylenegroups via a direct C—C linkage.

Non limitative examples of optionally substituted arylene groups ofwhich the rigid rod-forming arylene units (Ra) are composed, include:

and any of these groups substituted by at least one monovalentsubstituting group, as above defined, in particular by a phenylketonegroup.

Optionally substituted p-phenylenes are preferred as rigid rod-formingarylene units (Ra).

The above expressed definitions and preferences for recurring units (Ra)can be applied indifferently from each other to recurring units (Ra)possibly contained in the polyarylene (P1) as recurring units (R1), andto recurring units (Ra) possibly contained in the polyarylene (P2) asrecurring units (R2).

Rigid rod-forming arylene units (Ra), when contained in the polyarylenes(P1) and (P2), result in straight polymer chains exhibiting anoutstanding rigidity. For this reason, such polyarylenes are commonlyreferred to as “rigid-rod polymers”.

A second set of possible efficient arylene recurring units (R) iscomposed of optionally substituted arylene groups, the ends of which

-   -   either have a different direction, forming thus together an        angle between 0 and 180°, said angle being possibly acute or        obtuse,    -   or have the same direction and the same sense,    -   or have the same direction, are of opposite sense and are        disjoint (i.e. not in the straight foregoing of each other)        [globally hereafter referred to as kink-forming arylene units        (Rb)].

As above explained for recurring units (R) in general, kink-formingarylene units (Rb) are efficient, in that they are linked by each oftheir two ends to two other optionally substituted arylene groups via adirect C—C linkage.

A first subset of possible kink-forming arylene units (Rb) is composedof optionally substituted arylene groups, the ends of which have adifferent direction, forming together an acute angle [kink-formingarylene units (Rb-1)]. Non limitative examples of optionally substitutedarylene groups the ends of which have a direction different from eachother, include:

and any of these groups substituted by at least one monovalentsubstituting group, as above defined, in particular by a phenylketonegroup.

A second subset of possible kink-forming arylene units (Rb) is composedof optionally substituted arylene groups, the ends of which have adifferent direction, forming together an obtuse angle [kink-formingunits (Rb-2)]. Non limitative examples of optionally substituted arylenegroups the ends of which have a direction different from each other,include:

and any of these groups substituted by at least one monovalentsubstituting group, as above defined, in particular by a phenylketonegroup.

A third subset of possible kink-forming arylene units (Rb) is composedof optionally substituted arylene groups, the ends of which have thesame direction and the same sense [kink-forming arylene units (Rb-3)].Non limitative examples of optionally substituted arylene groups theends of which the same direction and the same sense include:

and any of these groups substituted by at least one monovalentsubstituting group, as above defined, in particular by a phenylketonegroup.

A fourth subset of possible kink-forming arylene units (Rb) is composedof optionally substituted arylene groups, the ends of which have thesame direction, are of opposite sense and are disjoint [kink-formingarylene units (Rb-4)]. Non limitative examples of such optionallysubstituted arylene groups include:

and any of these groups substituted by at least one monovalentsubstituting group, as above defined, in particular by a phenylketonegroup.

Preferably, kink-forming arylene units (Rb) are chosen from kink-formingarylene units (Rb-1), kink-forming arylene units (Rb-2) and kink-formingarylene units (Rb-4). More preferably, kink-forming arylene units (Rb)are chosen from kink-forming arylene units (Rb-1) and kink-formingarylene units (Rb-2). Still more preferably, kink-forming arylene units(Rb) are chosen from kink-forming arylene units (Rb-1). Even still morepreferably, kink-forming arylene units (Rb) are optionally substitutedm-phenylenes.

The above expressed definitions and preferences for recurring units (Rb)and its variations (Rb-1), (Rb-2), (Rb-3) and (Rb-4), can be appliedindifferently from each other to recurring units (Rb) possibly containedin the polyarylene (P1) as recurring units (R1), and to recurring units(Rb) possibly contained in the polyarylene (P2) as recurring units (R2).

Kink-forming arylene units (Rb), when contained in the polyarylenes (P1)and (P2), result in more or less kinked polymer chains, exhibiting ahigher solubility and fusibility than straight polymer chains. For thisreason, such polyarylenes are commonly referred to as “kinked polymers”.

The polyarylenes (P1) and (P2) may further comprise recurring units(R*), different from efficient arylene recurring units (R).

Recurring units (R*) may contain or not at least one strong divalentelectron withdrawing group linked on each of its ends to an arylenegroup. Non limitative examples of recurring units (R*) free of suchstrong divalent electron withdrawing group are:

Recurring units (R*) contain preferably at least one strong divalentelectron withdrawing group linked on each of its ends to an arylenegroup, in particular a p-phenylene group. The divalent electronwithdrawing group is preferably chosen from the sulfone group[—S(═O)₂—], the carbonyl group [—C(═O)—], the vinylene group [—CH═CH—],the sulfoxide group [—S(═O)—], the azo group [—N═N-], saturatedfluorocarbon groups like —C(CF₃)₂—, organic phosphine oxide groups[—P(═O)(═R_(h))—, where R_(h) is a hydrocarbyl group] and the ethylidenegroup [—C(═CA₂)—, where A can be hydrogen or halogen]. More preferably,the divalent electron withdrawing group is chosen from the sulfone groupand the carbonyl group. Still more preferably, recurring units (R*) arechosen from:

(i) recurring units of formula

(ii) recurring units of formula

wherein Q is a group chosen from

-   -   with R being

with n being an integer from 1 to 6 and n′ being an integer from 2 to 6,Q being preferably chosen from

(iii) recurring units of formula

(iv) recurring units of formula

wherein Q is as above defined.

Preferably more than 75 wt. % and more preferably more than 90 wt. % ofthe recurring units of the polyarylenes (P1) and (P2) are efficientarylene recurring units (R). Still more preferably, essentially all, ifnot all, the recurring units of the polyarylenes (P1) and (P2) areefficient arylene recurring units (R).

The polyarylenes (P1) and (P2) have a number average molecular weight ofadvantageously greater than 1000, preferably greater than 5000, morepreferably greater than about 10000 and still more preferably greaterthan 15000. On the other hand, the number average molecular weight ofthe polyarylenes (P1) and (P2) is usually below 100000, and preferablybelow 70000. The number average molecular weight of the polyarylenes(P1) and (P2) may be above 35000; alternatively, it may be of at most35000, 25000 or 20000. The number average molecular weight of apolyarylene, in particular that of the polyarylenes (P1) and (P2), isadvantageously determined by: (1) measuring a “relative” number averagemolecular weight of the polyarylene of conern by Gel PermeationChromatography (GPC) using polystyrene calibration standards, then (2)dividing the so-measured “relative” number average molecular weight by afactor 2. It is proceeded accordingly because the skilled in the art whois a specialist of polyarylenes knows that their “relative” numberaverage molecular weight, as measured by GPC, are generally off by afactor of about 2 times; it has already been accounted for thiscorrection factor in all the above cited lower and upper limits ofmolecular weight.

They can be amorphous (i.e. it has no melting point) or semi-crystalline(i.e. it has a melting point). They are preferably amorphous.

They have a glass transition temperature of advantageously above 50° C.,preferably above 120° C. and more preferably above 150° C.

The polyarylenes (P1) and (P2) can be prepared by any method. A methodwell known in the art to prepare them comprises polymerizing, preferablyby reductive coupling, (i) at least one dihaloarylene molecular compoundconsisting of an optionally substituted rigid rod-forming arylene group,which is linked on each of its two ends to one halogen atom, such aschlorine, bromine and iodine, with (ii) at least one dihaloarylenemolecular compounds consisting of an optionally substituted kink-formingarylene group, which is linked on each of its two ends to one halogenatom, such as chlorine, bromine, iodine, and fluorine. The eliminationof the halogen atoms from the dihaloarylene molecular compounds resultsin the formation of respectively optionally substituted rigidrod-forming and optionally substituted kink-forming arylene groups.

Thus, for example:

-   -   the elimination of both chlorine atoms from a molecule of        p-dichlorobenzene, p-dichlorobiphenyl or their homologous of        general formula Cl-(φ)_(N)-Cl, N being an integer from 3 to 10,        results in the formation of respectively 1, 2 or N adjacent        p-phenylene units (rigid rod-forming arylene units); thus,        p-dichlorobenzene, p-dichlorobiphenyl and their homologous of        general formula Cl-(φ)_(N)-Cl, N as above defined, can be        polymerized, so as to form p-phenylene units;    -   2,5-dichlorobenzophenone (p-dichlorobenzophenone) can be        polymerized, so as to form 1,4-(benzoylphenylene) units (also        rigid rod-forming arylene units);    -   m-dichlorobenzene can be polymerized, so as to form m-phenylene        units (kink-forming arylene units).

The combined weight of the polyarylene (P1) and of the polyarylene (P2),based on the total weight of the material, is advantageously above 25%,preferably above 50%, more preferably above 80%, and still morepreferably above 95%. Excellent results were obtained when the materialconsisted essentially of, or even consisted of, the polyarylene (P1) andthe polyarylene (P2).

Features Specific to the Polyarylene (P1)

The efficient arylene recurring units (R1) of the polyarylene (P1) mustbe of a very specific type, namely they must be a mix (M1) consistingof:

-   -   from 70 mole % to 100 mole %, based on the total number of moles        of efficient arylene recurring units (R1), of rigid rod-forming        arylene units (Ra), said rigid rod-forming arylene units (Ra)        being optionally substituted by at least one monovalent        substituting group        with    -   from 0 to 30 mole %, based on the total number of moles of        efficient arylene recurring units (R1), of kink-forming arylene        units (Rb), said kink-forming arylene units being optionally        substituted by at least one monovalent substituting group.

In the mix (M1), the number of moles of the kink-forming arylene units(Rb), based on the total number of moles of the efficient arylenerecurring units (R1), is preferably of at least 1.0%, more preferably atleast 5% and still more preferably at least 10%. On the other hand, inthe mix (M1), the number of moles of the kink-forming arylene units(Rb), based on the total number of moles of the efficient arylenerecurring units (R1), is preferably of at most 25%, more preferably atmost 21%, still more preferably at most 18%.

Good results were obtained when the efficient arylene recurring units(R1) of the polyarylene (P1) were a mix (M1) consisting of p-phenyleneunits substituted by a phenylketone group with unsubstituted m-phenyleneunits, in a mole ratio of about 85:15.

Good results were also obtained when the polyarylene (P1) was a kinkedrigid-rod polyphenylene copolymer, essentially all, if not all, therecurring units of which consisted of a mix (M1) of p-phenylenesubstituted by a phenylketone group with unsubstituted m-phenylene in amole ratio p-phenylene:m-phenylene of from 75:25 to 99.0:1.0, preferablyof from 79:21 to 95:5, more preferably of from 82:18 to 90:10, and stillmore preferably of about 85:15. Such a kinked rigid-rod polyphenylenecopolymer is commercially available from Solvay Advanced Polymers,L.L.C. as PRIMOSPIRE® PR-120 polyphenylene.

The weight of the polyarylene (P1), based on the total weight of thematerial, is advantageously of at least 1%, preferably of at least 5%,more preferably of at least 10% and still more preferably of at least15%. On the other hand, the weight of the polyarylene (P1), based on thetotal weight of the material, is advantageously of at most 99%,preferably of at most 95%, more preferably of at most 75% and still morepreferably of at most 60%.

In a certain particular embodiment of the present invention (Emb-A1),the weight of the polyarylene (P1), based on the total weight of thematerial, is of at least 35%, and ranges preferably from 35 to 60%. In acertain other particular embodiment of the present invention (Emb-B1),the weight of the polyarylene (P1), based on the total weight of thematerial, is below 35%, and ranges preferably between 35%, down to 15%.

In the present invention, one, two, three, or even more than threedifferent polyarylenes (P1) can be used.

Features Specific to the Polyarylene (P2)

The efficient arylene recurring units (R2) of the polyarylene (P2) mustbe of a very specific type, namely they must be a mix (M2) consistingof:

-   -   less than 70 mole %, down to 0 mole %, based on the total number        of moles of efficient arylene recurring units (R2), of rigid        rod-forming arylene units (Ra), said rigid rod-forming arylene        units (Ra) being optionally substituted by at least one        monovalent substituting group        with    -   more than 30 mole %, up to 100 mole %, based on the total number        of moles of efficient arylene recurring units (R2), of        kink-forming arylene units (Rb), said kink-forming arylene units        being optionally substituted by at least one monovalent        substituting group.

In the mix (M2), the number of moles of the kink-forming arylene units(Rb), based on the total number of moles of the efficient arylenerecurring units (R2), is preferably of at least 35%, more preferably atleast 40% and still more preferably at least 45%. On the other hand, inthe mix (M2), the number of moles of the kink-forming arylene units(Rb), based on the total number of moles of the efficient arylenerecurring units (R2), is preferably of at most 90%, more preferably atmost 75%, still more preferably at most 65% and most preferably at most55%.

Good results were obtained when the efficient arylene recurring units(R2) of the polyarylene (P2) were a mix (M2) consisting of p-phenyleneunits substituted by a phenylketone group with unsubstituted m-phenyleneunits, in a mole ratio of about 50:50.

Good results were also obtained when the polyarylene (P2) was a kinkedrigid-rod polyphenylene copolymer, essentially all, if not all, therecurring units of which consisted of a mix (M2) of p-phenylenesubstituted by a phenylketone group with unsubstituted m-phenylene in amole ratio p-phenylene:m-phenylene of from 25:75 to 65:35, preferably offrom 35:65 to 60:40, more preferably of from 45:55 to 55:45, and stillmore preferably of about 50:50. Such a kinked rigid-rod polyphenylenecopolymer is commercially available from Solvay Advanced Polymers,L.L.C. as PRIMOSPIRE® PR-250 polyphenylene.

The weight of the polyarylene (P2), based on the total weight of thematerial, is advantageously of at least 1%, preferably of at least 5%,more preferably of at least 25% and still more preferably of at least40%. On the other hand, the weight of the polyarylene (P2), based on thetotal weight of the material, is advantageously of at most 99%,preferably of at most 95%, more preferably of at most 90% and still morepreferably of at most 85%.

In a certain particular embodiment of the present invention [(Emb-A2),which is preferably the same embodiment as (Emb-A1), referred to in thechapter related to polyarylene (P1)], the weight of the polyarylene(P2), based on the total weight of the material, is of at most 65%, andranges preferably from 40 to 65%. In a certain other particularembodiment of the present invention [(Emb-B2), which is preferably thesame embodiment as (Emb-B 1), referred to in the chapter related topolyarylene (P1)], the weight of the polyarylene (P2), based on thetotal weight of the material, is above 65%, and ranges preferablybetween 65%, up to 85%.

The weight of the polyarylene (P2), based on the combined weight of thepolyarylene (P1) and the polyarylene (P2), is advantageously of at least1%, preferably of at least 5%, more preferably of at least 25% and stillmore preferably of at least 40%. On the other hand, the weight of thepolyarylene (P2), based on the combined weight of the polyarylene (P1)and the polyarylene (P2), is advantageously of at most 99%, preferablyof at most 95%, more preferably of at most 90% and still more preferablyof at most 85%.

In a certain particular embodiment of the present invention, the weightof the polyarylene (P2), based on the combined weight of the polyarylene(P1) and the polyarylene (P2), is of at most 65%, and ranges preferablyfrom 40 to 65%. In a certain other particular embodiment of the presentinvention, the weight of the polyarylene (P2), based on the combinedweight of the polyarylene (P1) and the polyarylene (P2), is above 65%,and ranges preferably between 65%, up to 85%.

In the present invention, one, two, three, or even more than threedifferent polyarylenes (P2) can be used.

In a second embodiment, the prosthetic device according to the presentinvention comprising at least one part consisting of a material furthercomprises at least one polyarylene (P1).

In a preferred embodiment, the prosthetic devices of the presentinvention are made of a material comprising high purity polyarylene(P2). When the material further comprises polyarylene (P1), high puritypolyarylene (P1) is also preferred. A high purity polyarylene isintended to denote a polyarylene featuring a purity of above 95%,preferably 98% and more preferably 99%.

Typical polyarylene contaminants are Ni, Zn and P.

High purity polyarylenes (P1) and (P2) contain advantageously less than10 ppm of Ni, preferably less than 9 ppm, more preferably less than 8ppm, still more preferably less than 6 ppm and most preferably less than2 ppm Ni.

High purity polyarylenes (P1) and (P2) contain advantageously less than200 ppm of Zn, preferably less than 150 ppm, more preferably less than100 ppm, still more preferably less than 80 ppm and most preferably lessthan 50 ppm Zn.

High purity polyarylenes (P1) and (P2) contain advantageously less than1000 ppm of P, preferably less than 800 ppm, more preferably less than700 ppm, still more preferably less than 600 ppm and most preferablyless than 500 ppm P.

High purity polyarylenes (P1) and (P2) contain preferably at the sametime less than 5 ppm Ni, less than 50 ppm Zn and less than 800 ppm P.

High purity polyarylenes may be obtained from prior art processes, suchas the one described in WO93/04099, WO93/14055, WO96/39455,WO2005/072374, the content of which are herein incorporated byreference. Additional treatments are preferably further carried out tosuch processes, and the reaction mixture obtained after polymerizationis preferably treated as follows. The reaction mixture is thenprecipitated in an anti-solvent and then the polymer is isolated. Thepolymer is then washed multiple times with the anti-solvent to extractthe residual dissolved catalysts which are converted to the metal saltswhich are soluble in the anti-solvents. Examples of anti-solvents areethanol, propanol, 2-butanone, aceton, methanol, isopropanol andmixtures thereof. Mixtures of these anti-solvents with water or acidicaqueous solutions gave also good results. Excellent results wereobtained using aceton, methanol, isopropanol. Such specific washingtreatment leads advantageously to the obtention of high puritypolyarylenes comprising low quantities of residuals, which make themespecially well suited for their use in medical applications and inparticular for the manufacture of prosthetic devices. High puritypolyarylenes (P1) and (P2) and combinations thereof feature excellentmechanical properties and a good biocompatibility which make themexcellent candidates for medical applications.

Another object of the present invention is thus related to the use ofhigh purity polyarylenes (P1) and (P2) in medical applications. Highpurity polyarylenes (P1) and (P2) and combinations thereof areespecially well suited for the manufacture of medical applicationdevices such as bone replacement applications, fibers and films formedical applications, fixation devices and medical instruments.

Optional Ingredients

The material described hereabove may further contain a variety of otherpolymers, additives, fillers, and the like, collectively calledingredients. Conventional ingredients of polyarylene compositions,include fibrous reinforcing agents, particulate fillers and nucleatingagents such as talc and silica, adhesion promoters, compatibilizers,curing agents, lubricants, metal particles, mold release agents, organicand/or inorganic pigments like TiO₂ and carbon black, dyes, flameretardants, smoke-suppressing agents, heat stabilizers, antioxidants, UVabsorbers, tougheners such as rubbers, plasticizers, anti-static agents,melt viscosity depressants such as liquid crystalline polymers and thelike.

In a particular embodiment, the material further comprises athermoplastic polymer selected from the group consisting of polyamides,polyimides, polyetherimides, polyamideimides, polyarylsulfones,polyphenylsulfones, polyetherketones, polyetheretherketones,polyetherketoneketones, polyarylene ethers, polyphenylene ethers,poly(2,6-dimethyl-1,4-phenylene ether), polyphenylene sulfides,polyethersulfones, polybenzimidazoles, polycarbonates, polyesters,polyolefins, poly(methyl pentene), polytetrafluoroethylene,polyethylene, polypropylene, liquid crystalline polymers, halogenatedpolymers, and mixtures thereof.

In another particular embodiment, the material further contains afibrous reinforcing agent, in particular an inorganic fibrousreinforcing agent such as glass fiber or carbon fiber. Thus, in acertain particular embodiment, the material comprises from 10 to 50 wt.%, in particular from 20 to 30 wt. %, of a reinforcing agent (allpercentages based on the total weight of the material); an example ofsuch a material is one composed of 35 wt. % of a polyarylene (P1), 35wt. % of polyarylene (P2) homopolymer and 30 wt. % of glass fiber.

In still another particular embodiment, the material further contains anadditive capable of promoting the formation of a char layer when thematerial is in contact with the flames of a fire [hereinafter, “charpromoter”]; without being bound by any theory, the char layer wouldprotect the core of material, slowing down its degradation. The charpromoter may be an organic compound, such as a phenoxy derivative;alternatively, it may be inorganic, such as an oxide, a salt, or acombination thereof. The char promoter is preferably a combination ofone or more oxides and one or more salts. Besides, the char promoter ispreferably composed of one or more oxides, salts or combinationsthereof, of one or more elements of families 3 to 12 of the PeriodicTable of the Elements, more preferably of one or more elements offamilies 6, 7 and 11, and still more preferably of one or more elementsselected from the group of Cr, Mo, W, Mn, Cu and Ag. Excellent resultsin terms of fire resistance were obtained when using CuCr₂O₄.MnO as thechar promoter. CuCr₂O₄.MnO is notably commercially available asEngelhard Meteor Plus 9875 Black brand pigment. In this particularembodiment, the material comprises generally between 0.01 and 10 wt. %of the char promoter, based on the total weight of the material. Thechar promoter amount is preferably of at least 0.1 wt. %, and verypreferably of at least 0.2 wt. %; besides, it is preferably of at most 5wt. %, and very preferably of at most 2 wt. %.

The weight of the optional ingredients, based on the total weight of thematerial, is advantageously below 75%, preferably below 50%, morepreferably below 25% and still more preferably below 10%. Excellentresults were obtained when the material was essentially free, or evenwas completely free, of said optional ingredients.

Embodiment (E*)

In still another a particular embodiment (E*), the material furthercomprises a poly(aryl ether sulfone), namely a polymer of which at least5 wt. % of the recurring units are recurring units of one ore moreformulae comprising at least one arylene group, at least one ether group(—O—) and at least one sulfone group [—S(═O)₂—].

The poly(aryl ether sulfone) may be a poly(biphenyl ether sulfone), inparticular a polyphenylsulfone. To the purpose of the present invention,a poly(biphenyl ether sulfone) is intended to denote polymer of whichmore than 50 wt. % of the recurring units are recurring units of one oremore formulae containing at least one p-biphenylene group:

at least one ether group (—O—) and at least one sulfone group[—S(═O)₂—].

To the purpose of the present invention, a polyphenylsulfone is intendedto denote any polymer of which more than 50 wt. % of the recurring unitsare recurring units:

In embodiment (E*), the polyarylenes (P1) and (P2) may meet all thecharacteristics of the polyphenylenes described in WO2006/094988, thecontent of which is herein incorporated by reference, as long as theyare compatible with those of respectively the polyarylenes (P1) and (P2)described in the present document.

The person skilled in the art will understand that the invention is notintended to be limited to this particular embodiment (E*), butencompasses also any embodiment other than (E*) which is described inthe present document. Besides, various modifications to the embodimentsdescribed in the present document will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other embodiments without departing from the spirit and scopeof the invention; thus, this invention is also not intended to belimited to all the embodiments shown, but is to be accorded the widestscope consistent with the principles and features disclosed herein.

The material as described above, while offering an exceptionally highlevel of strength and stiffness (similar to that provided by PRIMOSPIRE®PR-120 and PRIMOSPIRE® PR-250 polyphenylenes), further provides at leastone, preferably at least two and still more preferably all the followingadvantages:

the polymer material should have increased elongability; and/or

the polymer material should have increased impact resistance; and/or

the polymer material should have increased fire resistance.

which are illustrated in greater detail below by referring to theexamples; however, the present invention is not limited to theseexamples.

EXAMPLES

Polyarylene (P1*) was used as polyarylene (P1). Polyarylene (P1*) is akinked rigid-rod polyphenylene copolymer, essentially all, if not all,the recurring units of which consist of a mix of p-phenylene substitutedby a phenylketone group with unsubstituted m-phenylene in a mole ratiop-phenylene:m-phenylene of about 85:15; it has a glass transitiontemperature of about 158° C. Such a kinked rigid-rod polyphenylenecopolymer is commercially available from Solvay Advanced Polymers,L.L.C. as PRIMOSPIRE® PR-120 polyphenylene.

Polyarylene (P2*) was used as polyarylene (P2). Polyarylene (P2*) is akinked rigid-rod polyphenylene copolymer, essentially all, if not all,the recurring units of which consist of a mix of p-phenylene substitutedby a phenylketone group with unsubstituted m-phenylene in a mole ratiop-phenylene:m-phenylene of about 50:50; it has a glass transitiontemperature of about 165° C. Such a kinked rigid-rod polyphenylenecopolymer is commercially available from Solvay Advanced Polymers,L.L.C. as PRIMOSPIRE® PR-250 polyphenylene.

Polyarylene compositions (E1), (E2), (E3) and (E4) comprising variousproportions by weight of polyarylene (P2*) (and polyarylene (P1*)), wereprepared by melt-mixing the polyarylene (P2*) (and the polyarylene(P1*)) using a Brabender Plasticorder.

Polyarylene compositions (E1), (E2), (E3) and (E4), as well as neatpolyarylene control (P1*), were analyzed by standard physical testingmethods. Processing conditions and physical properties are shown inTable 1.

Example 1 Flexural Properties

Flexural properties were determined according to ASTM D790.

Notched Izod impact strength values were determined according to ASTMD256.

Unnotched Izod impact strength values were determined according to ASTMD4812.

The results are reported in table 1.

TABLE 1 Flexural properties results (P1*) control (E1) (E2) (E3) (E4)Polyarylene (P1*)(wt. %) 100 95 50 5 0 Polyarylene (P2*) (wt. %) 0 5 5095 100 Conditions of preparation Mixing temperature ° C. 290 290 290 300300 Torque reading (gram force-meter) 5000 4600 4150 2500 2300 Flexuralmodulus (Mpsi) (ASTM D-790) 1.12 1.1 1.01 0.89 0.86 Flexural strength(Kpsi) (ASTM D-790) 44.4 44.3 41.8 38.2 38.6 Flexural elongation (%)(ASTM D-790) 7.8 8.8 9.3 9.4 8.5

Surprisingly, polymer compositions (E1), (E2), (E3) and (E4), whileoffering an exceptionally high level of strength and stiffness (similarto that provided of PRIMOSPIRE® PR-120 and PRIMOSPIRE® PR-250 control(P1*)), further exhibited increased flexural elongation, in substantialprogress with (P1*) control [synergistic behaviour].

Example 2 Impact Resistance Properties

The notched and unnotched impact resistance of poyarlylene composition(E2) (according to the invention) and of control (P1*) was measured. Theresults are reported in table 2.

TABLE 2 Impact resistance results (P1*) control (E2) (E4) Polyarylene(P1*) (wt. %) 100 50 0 Polyarylene (P2*) (wt. %) 0 50 100 Notched Izodimpact strength times 10 7.6 13.0 11.6 (ft-lb/inch) (ASTM D-256)Unnotched Izod impact strength 17 21 20 (ft-lb/inch) (ASTM D-4812)

Surprisingly, polymer composition (E2), while offering an exceptionallyhigh level of strength and stiffness (similar to that provided ofPRIMOSPIRE® PR-120 and PRIMOSPIRE® PR-250 control (P1*)—see table 1),further exhibited increased impact resistance, both in terms of notchedand unnotched Izod, in substantial progress with (P1*) control[synergistic behavior].

Example 3 Biocompatibility Test Results

The biocompatibility of polyarylene (P2*) was tested using 4 standardtests covering cytotoxicity, sensitization, systemic toxicity andsubacute (subchronic toxicity).

ISO Guinea Pig Maximization Sensitization Test Results:

Pellets of polyarylene (P2*) were extracted according to ISO 10993-12.The resulting extracts and control blanks were injected to differentguinea pigs. On day 6, the dorsal site was reshaved and sodium laurylsulfate in mineral oil was applied. On day 7, the animals were topicallypatched with the appropriate test extract and the corresponding blankanimals were patched with the corresponding control blank. The patcheswere removed after 48±2 hours of exposure. Following a 2 week restperiod, the animals were topically patched with the appropriate testextract and the corresponding blank animals were patched with thecorresponding control blank. The patches were removed after 24±2 hoursof exposure. The dermal patch sites were observed for erythema and edema24±2 and 48±2 hours of exposure. Each animal was assessed for asensitization response based upon the dermal scores. None of them elicita sensitization response.

Minimum Essential Medium Elution Using L-929 Mouse Fibroblast Cells(ISO) (Cytotoxicity) Test Results:

Pellets of polyarylene (P2*) were extracted at 37±1° C. for 24-25 hours.The extract was inoculated onto the cell line and incubated at 37±1° C.in a humidified atmosphere with 5±1% CO₂ in the air. Cultures wereevaluated for cytotoxic effects by microscopic observations after 24, 48and 72 hours incubation periods. Polyarylene (P2*) was considerednon-toxic.

ISO Intracutaneous Reactivity Test:

Pellets of polyarylene (P2*) were extracted for 72±2 hours at 37±1° C.Two New Zealand white rabbits (Oryctolagus cuniculus) each received 5sequential 0.2 mL intracutaneous injections along either side of thedorsal mid-line with the test extract on one side and the controlextract on the other. The irritations reactions were scored at 24, 48and 72 hours post-injection on each rabbit for evidence of erythema andedema. Polyarylene (P2*) was considered as non-irritant.

ISO Acute Systemic Injection Test

Pellets of polyarylene (P2*) were extracted for 72±2 hours at 37±2° C.Groups of five albino, Swiss mice (Mus musculus) were injectedsystemically with test or control extracts at a dosing of 50 mL per kgbody weight. The animals were observed for signs of toxicity immediatelyafter injection and at 4, 24, 48 and 72 hours post injection.Polyarylene (P2*) was considered non-toxic.

The invention claimed is:
 1. A prosthetic device comprising at least onepart consisting of a material consisting of: at least one polyarylene(P2) comprising efficient arylene recurring units (R2), wherein theefficient arylene recurring units (R2) are a mix (M2) consisting of:less than 70 mole %, down to 0 mole %, based on the total number ofmoles of efficient arylene recurring units (R2), of rigid rod-formingarylene units (Ra), said rigid rod-forming arylene units (Ra) beingoptionally substituted by at least one monovalent substituting groupwith more than 30 mole %, up to 100 mole %, based on the total number ofmoles of efficient arylene recurring units (R2), of kink-forming aryleneunits (Rb), said kink-forming arylene units being optionally substitutedby at least one monovalent substituting group, and optionally at leastone additive selected from the group consisting of fibrous reinforcingagents, char promoters, particulate fillers, nucleating agents, adhesionpromoters, compatibilizers, curing agents, lubricants, metal particles,mold release agents, organic and/or inorganic pigments, dyes, flameretardants, smoke-suppressing agents, heat stabilizers, antioxidants, UVabsorbers, tougheners, plasticizers, anti-static agents, and meltviscosity depressants, wherein the prosthetic device is an orthopaedicprosthesis, a dental structure, an artificial body part selected fromthe group consisting of limbs, eyes, and implants, or a fixed prostheticanatomical device.
 2. A prosthetic device as claimed in claim 1, whereinsaid prosthetic device is: an orthopaedic prosthesis comprising amanufactured replacement for an end and/or an articulating surface of abone; a manufactured replacement for a portion of a bone distant from anarticulating surface; or an artificial body part selected from the groupconsisting of limbs, eyes, and implants.
 3. A prosthetic device asclaimed in claim 1, wherein said prosthetic device is an orthopaedicprosthesis.
 4. The prosthetic device according to claim 1, whereinessentially all the recurring units of the polyarylene (P2) are saidefficient arylene recurring units (R2).
 5. The prosthetic deviceaccording to claim 1, wherein all the recurring units of the polyarylene(P2) are said efficient arylene recurring units (R2).
 6. The prostheticdevice according to claim 1, wherein all the recurring units of thepolyarylene (P2) are said efficient arylene recurring units (R2) andsaid mix (M2) consists of p-phenylene units substituted by aphenylketone group with unsubstituted m-phenylene units, in a mole ratioof about 50:50.
 7. The prosthetic device according to claim 1, whereinall the recurring units of the polyarylene (P2) are said efficientarylene recurring units (R2) and said mix (M2) consists of p-phenyleneunits substituted by a phenylketone group with unsubstituted m-phenyleneunits, in a mole ratio of about 25:75 to 65:35.
 8. The prosthetic deviceaccording to claim 1, wherein all the recurring units of the polyarylene(P2) are said efficient arylene recurring units (R2) and said mix (M2)consists of p-phenylene units substituted by a phenylketone group withunsubstituted m-phenylene units, in a mole ratio of about 35:65 to60:40.
 9. The prosthetic device according to claim 1, wherein all therecurring units of the polyarylene (P2) are said efficient arylenerecurring units (R2) and said mix (M2) consists of p-phenylene unitssubstituted by a phenylketone group with unsubstituted m-phenyleneunits, in a mole ratio of about 45:55 to 55:45.
 10. The prostheticdevice according to claim 1, wherein said mix (M2) consists ofp-phenylene units substituted by a phenylketone group with unsubstitutedm-phenylene units, in a mole ratio of about 50:50.
 11. The prostheticdevice according to claim 1, wherein said polyarylene (P2) comprisesless than 10 ppm of Ni, less than 200 ppm of Zn, and less than 1000 ppmof P.
 12. The prosthetic device according to claim 1, wherein saidpolyarylene (P2) comprises less than 5 ppm Ni, less than 50 ppm Zn, andless than 800 ppm P.
 13. The prosthetic device according to claim 1,wherein said material consists of said at least one polyarylene (P2).14. The prosthetic device according to claim 1, wherein said materialconsists of said at least one polyarylene (P2) and said at least oneadditive.
 15. The prosthetic device according to claim 14, wherein saidmaterial comprises a char promoter.
 16. The prosthetic device accordingto claim 15, wherein said char promoter is a phenoxy derivative.
 17. Theprosthetic device according to claim 15, wherein said char promoter isan inorganic oxide, a salt, or a combination thereof.
 18. The prostheticdevice according to claim 17, wherein said char promoter is acombination of one or more oxides and one or more salts.
 19. Theprosthetic device according to claim 15, wherein said char promoter isCuCr₂O₄.MnO.
 20. The prosthetic device according to claim 15, whereinthe material comprises between 0.01 and 10 wt. % of the char promoter,based on the total weight of the material.